Image display apparatus, image signal processing method, program for implementing the method, and storage medium storing the program

ABSTRACT

An image display apparatus which is capable of optimizing the image quality of a plurality of display devices having different optical characteristics when carrying out processing of an image signal supplied to the display devices, without providing a dedicated display driving circuit for each display device. The image display apparatus comprises a plurality of liquid crystal display panels ( 10, 11 ) having different optical characteristics. A liquid crystal driving circuit ( 2 ) processes an image signal outputted to the liquid crystal display panels ( 10, 11 ). Operative states of the liquid crystal display panels ( 10, 11 ) are detected. At least one processing characteristic of the liquid crystal driving circuit ( 2 ) is changed according to the detected operative states.

This is a continuation of Ser. No. 12/544,708, filed Aug. 20, 2009, nowU.S. Pat. No. 8,212,743, which is a continuation of Ser. No. 11/145,556,filed Jun. 3, 2005, now U.S. Pat. No. 7,755,567, the contents of whichare herein incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image display apparatus, and animage signal processing method, which carry out processing of an imagesignal supplied to a plurality of display devices having differentoptical characteristics, using a common display driving circuit, and aprogram for implementing the method, and a storage medium storing theprogram.

2. Description of the Related Art

Conventionally, there has been known a liquid crystal display apparatuswhich, when carrying out brightness adjustment of an image signal, canrealize sufficient gradation displays, even if the amplitude of theimage signal is reduced. Further, there has been known a cameraintegrated-type VTR provided with a direct view-type liquid crystaldisplay panel and a finder view-type liquid crystal display panel. Withthis camera integrated-type VTR, a method is employed in which the twodisplay panels are each driven by a dedicated driving circuit. This isdue to the fact that optical characteristics such as gamma, brightness,contrast, and white balance, differ according to the type of liquidcrystal display panel, and thus, an independent driving system must beprovided for each type.

FIG. 5 is a block diagram schematically showing the electricalconfiguration of a conventional liquid crystal display apparatus. Thisliquid crystal display apparatus is comprised of a direct view-typeliquid crystal display panel 110, a first liquid crystal driving circuit102 a that drives the direct view-type liquid crystal display panel 110,a finder view-type liquid crystal display panel 111, and a second liquidcrystal driving circuit 102 b that drives the finder view-type liquidcrystal display panel 111.

The first liquid crystal driving circuit 102 a includes a contrastadjusting circuit 103 a that adjusts the amplitude of an image signal, abrightness adjusting circuit 104 a that adjusts setup levels of theimage signal, a gamma adjusting circuit 105 a that adjusts gammacharacteristics of the image signal, and a memory 106 a. The secondliquid crystal driving circuit 102 b includes a contrast adjustingcircuit 103 b that adjusts the amplitude of the image signal, abrightness adjusting circuit 104 b that adjusts setup levels of theimage signal, a gamma adjusting circuit 105 b that adjusts gammacharacteristics of the image signal, and a memory 106 b.

With the image display apparatus having the above configuration, when animage signal that has been converted to the RGB format by a decoder, notshown, is inputted via an input terminal 101, the image signal issupplied to the first liquid crystal driving circuit 102 a, where signalprocessing is carried out on the image signal by the contrast adjustingcircuit 103 a, the brightness adjusting circuit 104 a, the gammaadjusting circuit 105 a, an inversion circuit, not shown, etc., and thenthe processed image signal is supplied to the direct view-type liquidcrystal display panel 110, whereby an image is displayed. At this time,adjustment values for carrying out the above signal processing are setto the contrast adjusting circuit 103 a, the brightness adjustingcircuit 104 a, and the gamma adjusting circuit 105 a, based on firstcontrol data 107 that is stored in the memory 106 a.

Further, the image signal that is inputted via the input terminal 101 issimultaneously supplied to the second liquid crystal driving circuit 102b. After signal processing is carried out on the image signal by thecontrast adjusting circuit 103 b, the brightness adjusting circuit 104b, the gamma adjusting circuit 105 b, an inversion circuit, not shown,etc., the image signal is supplied to the finder-type liquid crystaldisplay panel 111, whereby an image is displayed. At this time,adjustment values for carrying out the above signal processing are setto the contrast adjusting circuit 103 b, the brightness adjustingcircuit 104 b, and the gamma adjusting circuit 105 b, based on secondcontrol data 108 that is stored in the memory 106 b.

In this way, with the conventional image display apparatus, it ispossible to set optimum settings for the direct view-type liquid crystaldisplay panel and for the finder-type liquid crystal display panel.

However, with the above conventional image display apparatus, furtherimprovements are demanded in the following points. That is, theprovision of two sets of liquid crystal driving circuits on the imagedisplay apparatus is disadvantageous in terms of the area for mountingcomponent parts, power consumption, and cost, and thus, it is difficultto provide an apparatus having a small size, reduced power consumption,and a low cost.

Further, when a plurality of liquid crystal panels such as a directview-type liquid crystal display panel, and a finder view-type liquidcrystal display panel, are employed in a camera integrated-type VTR,since the optical characteristics of the liquid crystal panels differ,the optimum set values of brightness, contrast, gamma, and the like,differ between the liquid crystal panels. In addition, in recent years,white light emitting diodes (hereinafter referred to as “white LEDs”)are used as a light source for backlight for liquid crystal displays.However, the white LEDs have large variations in chromaticity due totheir characteristics. Conventionally, such variations are corrected onthe liquid crystal panels by providing offset for the setup of R, G, Bimage signals. Therefore, even if the optical characteristics of thedirect view-type liquid crystal display panel and the finder view-typeliquid crystal display panel were the same, if the chromaticity of thebacklight that is combined differs, the optimum set values for imagesignals become different between the liquid crystal panels.

As mentioned above, if these two liquid crystal display panels aredriven by respective dedicated driving circuits, it is possible tosupply an optimum image signal for each liquid crystal display panel.However, in this case, two sets of liquid crystal driving circuits areused, which is disadvantageous in terms of the area for mountingcomponent parts, power consumption, and cost, and thus, it is difficultto provide an apparatus having a small size, reduced power consumption,and a low cost.

On the other hand, if the two liquid crystal panels are driven by asingle driving circuit, optimum image signals cannot be supplied to bothof the liquid crystal display panels, and there arises a problem thatthe image quality of either one of the display panels becomes degraded.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an image displayapparatus and an image signal processing method which are capable ofoptimizing the image quality of a plurality of display devices havingdifferent optical characteristics when carrying out processing of animage signal supplied to the display devices, without providing adedicated display driving unit for each display device, and a programfor implementing the method and a storage medium storing the program.

To attain the above object, in a first aspect of the present inventionthere is provided an image display apparatus comprising a plurality ofdisplay devices having different optical characteristics, a displaydriving unit that processes an image signal outputted to the pluralityof display devices, a detecting unit that detects operative states ofthe plurality of display devices, and a changing unit that changes atleast one processing characteristic of the display driving unitaccording to the detected operative states.

According to the first aspect of the present invention, when processingof an image signal supplied to the plurality of display devices havingdifferent optical characteristics is carried out using a common displaydriving unit, operative states of the plurality of display devices aredetected, and processing characteristics of the display driving unit arechanged according to the detected operative states. Therefore, whencarrying out processing of an image signal supplied to the plurality ofdisplay devices having different optical characteristics, it is possibleto optimize the image quality of the display devices without providing adedicated display driving unit for each display device. As a result, itis possible to reduce the area for mounting component parts, powerconsumption and costs.

Preferably, the changing unit comprises a setting value holding unitthat holds a plurality of setting values which determine the processingcharacteristic of the display driving unit, and a selecting unit thatselects one of the held plurality of setting values according to thedetected operative states, and the changing unit changes the processingcharacteristic of the display driving unit by setting the selectedsetting value to the display driving unit.

According to this construction, it is possible to easily change theprocessing characteristics of the display driving unit.

Preferably, the detecting unit comprises an open-close detecting unitthat detects an open-close state of a predetermined one of the displaydevices, and changes the processing characteristic of the displaydriving unit based on the detected open-close state.

Alternatively, the detecting unit comprises a rotation detecting unitthat detects a rotational state of a predetermined one of the displaydevices, and changes the processing characteristic of the displaydriving unit based on the detected rotational state.

Preferably, the detecting unit comprises an open-close detecting unitthat detects an open-close state of a predetermined one of the displaydevices, a rotation detecting unit that detects a rotational state ofthe predetermined display device, and a control unit that controlsdisplay operations of the display devices based on the detectedopen-close state and rotational state.

According to this construction, the processing characteristic of thedisplay driving unit can be automatically changed according to theopen-close state and the rotational state of the display devices.

More preferably, the image display apparatus comprises a switching unitthat switches an image quality-prioritizing in which priority is givento image quality of an image to be displayed on one of the plurality ofdisplay devices, and the changing unit comprises a second selecting unitthat selects a setting value from the setting values held by the settingvalue holding unit, according to the switching of the switching unit.

According to this construction, the image quality can be adjusted asdesired according to the user's intention.

Preferably, the processing characteristic of the display driving unitthat is changed by the changing unit comprises at least onecharacteristic selected from the group consisting of brightness,contrast, gamma, and white balance of the image signal.

Preferably, the plurality of display devices comprise a first displaydevice, and a second device, and the plurality of setting valuescomprise at least two setting values selected from the group consistingof a first setting value that is most suitable for opticalcharacteristics of the first display device, a second setting value thatis most suitable for optical characteristics of the second displaydevice, and a third setting value that is an approximately middle valueof the first and second setting values.

According to this construction, whether only the first display device isdriven, or only the second display device is driven, or both the firstand the second display devices are driven, or either one is driven, itis possible to set the adjustment values to values for obtainingsuitable image quality.

More preferably, the plurality of setting values further comprise atleast one setting value selected from the group consisting of a fourthsetting value that is closer to the first setting value with respect tothe approximately middle value, and a fifth setting value that is closerto the second setting value with respect to the approximately middlevalue.

According to this construction, when the first and second displaydevices are driven simultaneously, or either one is driven, it ispossible to give priority to the image quality of the first displaydevice or the second display device.

More preferably, the first display device is provided on the imagedisplay apparatus such that it can be freely opened and closed and canbe freely rotated relative to the image display apparatus, and thesecond display device is fixed to the image display apparatus, and theimage display apparatus further comprises a control unit that controlsdisplay operations of the first display device and the second displaydevice, based on an open-close state and a rotational state of the firstdisplay device.

According to this construction, the image quality of the first andsecond display devices can be suitably set according to the open-closestate and the rotational state of the first display device.

More preferably, the plurality of display devices comprise liquidcrystal display panels.

To attain the above object, in a second aspect of the present invention,there is provided an image signal processing method of processing animage signal supplied to a plurality of display devices having differentoptical characteristics, using a display driving unit, comprising adetecting step of detecting operative states of the plurality of displaydevices, and a changing step of changing at least one processingcharacteristic of the display driving unit according to the detectedoperative states.

To attain the above object, in a third aspect of the present invention,there is provided a program for causing a computer to execute an imagesignal processing method of processing an image signal supplied to aplurality of display devices having different optical characteristics,using a display driving unit, comprising a detecting module fordetecting operative states of the plurality of display devices, and achanging module for changing at least one processing characteristic ofthe display driving unit according to the detected operative states.

To attain the above object, in a fourth aspect of the present invention,there is provided a computer-readable storage medium storing a programfor causing a computer to execute an image signal processing method ofprocessing an image signal supplied to a plurality of display deviceshaving different optical characteristics, using a display driving unit,the program comprising a detecting module for detecting operative statesof the plurality of display devices, and a changing module for changingat least one processing characteristic of the display driving unitaccording to the detected operative states.

The above and other objects, features, and advantages of the presentinvention will become more apparent from the following detaileddescription taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the appearance of a cameraintegrated-type VTR including an image display apparatus according to anembodiment of the present invention;

FIG. 2 is a block diagram schematically showing the electricalconfiguration of the camera integrated-type VTR;

FIG. 3 is a view showing a table showing adjustment values for controldata in a memory appearing in FIG. 2;

FIG. 4 is a flowchart showing the procedure of a process for settingadjustment values for a contrast adjusting circuit, a brightnessadjusting circuit, and a gamma adjusting circuit; and

FIG. 5 is a block diagram schematically showing the electricalconfiguration of a conventional liquid crystal display apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described in detail with reference tothe drawings showing a preferred embodiment thereof.

FIG. 1 is a perspective view showing the appearance of a cameraintegrated-type VTR including an image display apparatus according to anembodiment of the present invention. The camera integrated-type VTR 20has a direct view-type liquid crystal display panel 10 provided on aside surface of the main body thereof, and a finder view-type liquidcrystal display panel 11 provided on a back surface of the main bodythereof. The direct view-type liquid crystal display panel 10 can befreely opened and closed in a direction indicated by the arrow A and canbe freely rotated in a direction indicated by the arrow B, about a hingesection 30 relative to the main body of the camera integrated-type VTR20.

FIG. 2 is a block diagram schematically showing the electricalconfiguration of the camera integrated-type VTR 20.

As shown in FIG. 2, the camera integrated-type VTR 20 is comprised of alens 15, a CCD 16, a camera signal processing circuit 17, a recordercircuit 18, a liquid crystal driving circuit 2, a microcomputer 14, thedirect view-type liquid crystal display panel 10, and the finderview-type liquid crystal display panel 11. Connected to themicrocomputer 14 are the following: an open-close detecting switch (SW)12 that detects an open-close state of the direct view-type liquidcrystal display panel 10; a rotation detecting switch (SW) 13 thatdetects the rotational state of the direct view-type liquid crystaldisplay panel 10; and a change-over switch (SW) 25 that gives priorityto either the direct view-type liquid crystal display panel 10 or thefinder view-type liquid crystal display panel 11 so as to display one ofthe display panels with higher image quality. The liquid crystal drivingcircuit 2 is comprised of a contrast adjusting circuit 3 that adjuststhe amplitude of an image signal, a brightness adjusting circuit 4 thatadjusts setup levels of the image signal, a gamma adjusting circuit 5that adjusts gamma characteristics of the image signal, and an inversioncircuit, not shown, a memory 6. First control data 7, second controldata 8, third control data 9, fourth control data 21, and fifth controldata 22 are stored in the memory 6.

FIG. 3 is a view showing a table showing adjustment values for thecontrol data in the memory 6 shown in FIG. 2. In FIG. 3, the adjustmentvalues of contrast, brightness, and gamma of the first control data 7are set such that the values are most suitable for opticalcharacteristics of the direct view-type liquid crystal display panel 10.In the first control data 7, the adjustment values of contrast,brightness, and gamma are set to values A1, B1, and C1, respectively.The adjustment values of contrast, brightness, and gamma of the secondcontrol data 8 are set such that the values are most suitable foroptical characteristics of the finder view-type liquid crystal displaypanel 11. In the second control data 8, the adjustment values ofcontrast, brightness, and gamma are set to values A2, B2, and C2,respectively.

The adjustment values of contrast, brightness, and gamma of the thirdcontrol data 9 are each set to a value that is an approximately middlevalue of the corresponding adjustment values of the first and secondcontrol data which are set so as to obtain optimum image quality forboth the direct view-type liquid crystal display panel 10 and the finderview-type liquid crystal display panel 11. In the third control data 9,the adjustment values of contrast, brightness, and gamma are set tovalues A3, B3, and C3, respectively. The adjustment values A3, B3, andC3, are calculated based on the adjustment values A1, B1, and C1 set inthe first control data 7, and the adjustment values A2, B2, and C2 setin the second control data 8, according to the following formula (1).A3≈½(A1+A2)B3≈½(B1+B2)C3≈½(C1+C2) . . .   (1)

The adjustment values of contrast, brightness, and gamma of the fourthcontrol data 21 are each set to a value that is closer to a value thatobtains optimum image quality for the direct view-type liquid crystaldisplay panel 10 with respect to the approximately middle value of thecorresponding adjustment values of the first and second control datawhich are set so as to obtain optimum image qualities for both thedirect view-type liquid crystal display panel 10 and the finderview-type liquid crystal display panel 11. In the fourth control data21, the adjustment values of contrast, brightness, and gamma are set tovalues A4, B4, and C4, respectively. The adjustment values A4, B4, andC4 are calculated based on the adjustment values A1, B1, and C1 set inthe first control data 7, and the adjustment values A2, B2, and C2 setin the second control data 8, according to the following formula (2).A1<A4<½(A1+A2)B1<B4<½(B1+B2)C1<C4<½(C1+C2)   (2)

The adjustment values of contrast, brightness, and gamma of the fifthcontrol data 22 are each set to a value that is closer to a value thatobtains optimum image quality for the finder view-type liquid crystaldisplay panel 11 with respect to the approximately middle value of thecorresponding adjustment values of the first and second control datawhich are set so as to obtain optimum image qualities for both thedirect view-type liquid crystal display panel 10 and the finderview-type liquid crystal display panel 11. In the fifth control data 22,the adjustment values of contrast, brightness, and gamma are set tovalues A5, B5, and C5, respectively. The adjustment values A5, B5, andC5, are calculated based on the adjustment values A1, B1, and C1 set inthe first control data 7, and the adjustment values A2, B2, and C2 setin the second control data 8, according to the following formula (3).½(A1+A2)<A5<A2½(B1+B2)<B5<B2½(C1+C2)<C5<C2   (3)

Next, the operation of the camera integrated-type VTR 20 constructed asabove will be described.

First, an optical image of a subject that is inputted via the lens 15 isformed on the CCD 16, and is photoelectrically converted into anelectrical signal by the CCD 16. The electrical signal is supplied tothe camera signal processing circuit 17. The image signal is imageprocessed by the camera signal processing circuit 17 and supplied to therecorder circuit 18. After being subjected to signal processing by therecorder circuit 18, the image signal is stored in a storage medium by arecorder, not shown. At the same time, the image signal (RGB signal)from the recorder circuit 18 is outputted to an external apparatus via avideo output terminal 19 and to the liquid crystal driving circuit 2 viathe input terminal 1.

The image signal which is outputted to the liquid crystal drivingcircuit 2 via the input terminal 1 is subjected to signal processing bythe contrast adjusting circuit 3, the brightness adjusting circuit 4,the gamma adjusting circuit 5, the inversion circuit, not shown, etc.Then, the processed image signal is outputted to the direct view-typeliquid crystal display panel 10 and the finder view-type liquid crystaldisplay panel 11, and thus, an image is displayed on the directview-type liquid crystal display panel 10 and the finder view-typeliquid crystal display panel 11.

Here, the adjustment values are set in the contrast adjusting circuit 3,the brightness adjusting circuit 4, and the gamma adjusting circuit 5,based on the first control data 7, or the second control data 8, or thethird control data 9, which are stored in the memory 6.

As stated before, the direct view-type liquid crystal display panel 10can be freely opened and closed and also can be freely rotated about thehinge section 30, and the open-close state is detected by the open-closedetecting switch 13, and the rotational state is detected by therotation detecting switch 13. The results of these detections aresupplied to the microcomputer 14. Based on the detection results, themicrocomputer 14 controls the selection as to whether the image is to bedisplayed only on the direct view-type liquid crystal display panel 10,or only on the finder view-type liquid crystal display panel 11, or onboth the direct view-type liquid crystal display panel 10 and the finderview-type liquid crystal display panel 11. The microcomputer 14 controlsthe memory 6 so that, if the image is to be display only on the directview-type liquid crystal display panel 10, the first control data 7 isselected, if the image is to be display only on the finder view-typeliquid crystal display panel 11, the second control data 8 is selected,and if the image is to be displayed on both the direct view-type liquidcrystal display panel 10 and the finder view-type liquid crystal displaypanel 11, the third control data 9 is selected. Based on the selectedcontrol data, the adjustment values of the contrast adjusting circuit 3,the brightness adjusting circuit 4, and the gamma adjusting circuit 5are set.

When the image is to be displayed on both the direct view-type liquidcrystal display panel 10 and the finder view-type liquid crystal displaypanel 11, the fourth control data 21 may be used as an alternative tothe third control data 9. In this case, the VTR 20 enters an imagequality-prioritizing mode in which priority is given to the imagequality of the direct view-type liquid crystal display panel 10.Similarly, the fifth control data 22 may be used as an alternative tothe third control data 9. In this case, the VTR 20 enters an imagequality-prioritizing mode in which priority is given to the imagequality of the finder view-type liquid crystal display panel 11. Theuser can switch these image quality-prioritizing modes by operating thechange-over switch 25.

FIG. 4 is a flowchart showing the procedure of the procedure of aprocess for setting the adjustment values for the contrast adjustingcircuit 3, the brightness adjusting circuit 4, and the gamma adjustingcircuit 5. The program for carrying out this process is stored in a ROM,not shown, within the microcomputer 14, and is executed by a CPU, notshown, within the microcomputer 14.

First, the states of the open-close detecting switch 12 and the rotationdetecting switch 13 are read (steps S1 and S2). Based on the read statesof the open-close detecting switch 12 and the rotation detecting switch13, the display panel on which the image is to be displayed, is selected(step S3). Here, the selection of the display panel is carried out suchthat the image is displayed in the following manner. That is, if thedirect view-type liquid crystal display panel 10 is in a state such thatit has been opened in the direction indicated by the arrow A (refer toFIG. 1), the image is displayed only on the direct view-type liquidcrystal display panel 10, and is not displayed on the finder view-typeliquid crystal display panel 11. If the direct view-type liquid crystaldisplay panel 10 is rotated from the state of FIG. 1 in the directionindicated by the arrow B, and the display screen is faced toward thesubject, the image is displayed on the direct view-type liquid crystaldisplay panel 10, and at the same time, is displayed on the finderview-type liquid crystal display panel 11. Further, if the displaysurface of the direct view-type liquid crystal display panel 10 isstored with the display screen facing the main body of the cameraintegrated-type VTR 20, the image is displayed only on the finderview-type liquid crystal display panel 11 and is not displayed on thedirect view-type liquid crystal display panel 10.

Next, the selected crystal display panel is determined (step S4). If itis determined that only the direct view-type liquid crystal displaypanel 10 has been selected, the first control data 7 which is mostsuitable for the optical characteristics of the direct view-type liquidcrystal display panel 10 is read (step S5), and using this first controldata 7, the adjustment values A1, B1, C1 for the contrast adjustingcircuit 3, the brightness adjusting circuit 4, and the gamma adjustingcircuit 5 are set respectively (step S6), followed by termination of theprocess.

If it is determined in the step S4 that only the finder view-type liquidcrystal display panel 11 has been selected, the second control data 8 isread (step S7), and using this second control data 8, the adjustmentvalues A2, B2, C2 for the contrast adjusting circuit 3, the brightnessadjusting circuit 4, and the gamma adjusting circuit 5 are setrespectively in a step S6, followed by termination of the process.

If it is determined in the step S4 that both the direct view-type liquidcrystal display panel 10 and the finder view-type liquid crystal displaypanel 11 have been selected, it is determined whether the user hasinstructed switching of the image quality-prioritizing mode by operatingthe change-over switch 25 (step S8). If switching of the imagequality-prioritizing mode has not been instructed by the user, the thirdcontrol data 9 is read (step S9), and using this third control data 9,the adjustment values A3, B3, C3 for the contrast adjusting circuit 3,the brightness adjusting circuit 4, and the gamma adjusting circuit 5are set respectively (step S6), followed by termination of the process.

On the other hand, if switching of the image quality-prioritizing modehas been instructed by the user in the step S8 and priority is given tothe direct view-type liquid crystal display panel 10, the fourth controldata 21 is read (step S10), and using this fourth control data 21, theadjustment values A4, B4, C4 for the contrast adjusting circuit 3, thebrightness adjusting circuit 4, and the gamma adjusting circuit 5 areset respectively (step S6), followed by termination of the process. If,in the step S8, an instruction has been given to give priority to thefinder view-type liquid crystal display panel 11, the fifth control data22 is read (step S11), and using this fifth control data 22, theadjustment values A5, B5, C5 for the contrast adjusting circuit 3, thebrightness adjusting circuit 4, and the gamma adjusting circuit 5 areset respectively (step S6), followed by termination of the process.

As described above, according to the present embodiment, when processingan image signal supplied to the direct view-type liquid crystal displaypanel 10 and the finder view-type liquid crystal display panel 11, it ispossible to optimize the image quality of the liquid crystal panelswithout providing liquid crystal driving circuits dedicated to therespective display panels. As a result, it is possible to reduce thearea for mounting component parts, power consumption and costs.

That is, when the microcomputer 14 drives only the direct view-typeliquid crystal display panel 10, the liquid crystal driving circuit 2 iscontrolled using a combination of adjustment values (combination ofadjustment values of control signals for adjusting brightness, contrast,and gamma) most suitable for the optical characteristics of the directview-type liquid crystal display panel 10, and when the microcomputer 14drives only the finder view-type liquid crystal display panel 11, theliquid crystal driving circuit 2 is controlled using a combination ofadjustment values most suitable for the optical characteristics of thefinder view-type liquid crystal display panel 11. Thus, when either oneof the liquid crystal display panels, i.e. the direct view-type liquidcrystal display panel 10 or the finder view-type liquid crystal displaypanel 11, is selected, it is possible to drive the liquid crystaldisplay panel with the most suitable image quality for the selectedpanel.

Further, when both the direct view-type liquid crystal display panel 10and the finder view-type liquid crystal display panel 11 are drivensimultaneously, the liquid crystal driving circuit 2 is controlled usinga combination of adjustment values which are set to approximately middlevalues of the adjustment values set for the direct view-type liquidcrystal display panel 10 and the adjustment values set for the finderview-type liquid crystal display panel 11. Thus, it is possible todisplay an image that is not degraded in quality, on each liquid crystaldisplay panel. Further, when an image is displayed simultaneously on thetwo liquid crystal display panels, it is possible to give priority tothe image quality of the direct view-type liquid crystal display panel10 or give priority to the image quality of the finder view-type liquidcrystal display panel 11, by switching the image quality-prioritizingmode.

While the embodiment of the present invention has been described above,the present invention is not limited to the configuration of theembodiment, and may be realized in any configuration that can achievethe functions exhibited by the configuration of the embodiment.

For example, the present embodiment shows a case where two liquidcrystal display panels are provided. However, three or more liquidcrystal display panels may be provided. Further, in the presentembodiment, the display operation is controlled according to theopen-close state and the rotational state of the liquid crystal displaypanel. However, it is possible to control the display operation of theliquid crystal display panel according to the operative state of eitherthe open-close state or the rotational state. Further, it is possible toselect control data that is suitable for optical characteristics of theliquid crystal display panels according to either the open-close stateor the rotational state. Moreover, in the present embodiment, contrast,brightness, and gamma are used as the adjustment values for opticalcharacteristics of the liquid crystal display panels. However,adjustment values other than these adjustment values, for example, whitebalance, may be used. Further, adjustment values of contrast,brightness, and gamma that are set according to a user's preference forone or both liquid crystal display panels may be stored as sixth controldata in the memory or the like.

Further, although in the present embodiment liquid crystal displaypanels are used as display devices, it is possible to use organic ELdisplays, plasma displays or the like.

It is to be understood that the object of the present invention may bealso accomplished by supplying an image display apparatus with a storagemedium in which a program code of software, which realizes the functionsof the above described embodiment, is stored, and causing a computer (orCPU or MPU) of the apparatus to read out and execute the program codestored in the storage medium.

In this case, the program code itself read from the storage mediumrealizes the functions of the above described embodiment, and hence theprogram code and the storage medium in which the program code is storedconstitute the present invention.

Examples of the storage medium for supplying the program code is notlimited to a ROM or the like, but may be, for example, a memory cardsuch as a compact flash (registered trademark).

This application claims priority from Japanese Patent Application No.2004-166332 filed Jun. 3, 2004, which is hereby incorporated byreference herein.

What is claimed is:
 1. An image display control apparatus comprising: aholding unit that holds a plurality of control data; a common displaycontroller that processes an image signal based on a control data, whichdetermine a processing characteristic of said common display controller,and outputs the processed image signal to a plurality of displaydevices; a detecting unit that detects operative states of saidplurality of display devices; and a selecting unit that selects onecontrol data of the held plurality of control data according to thedetected operative states, wherein said common display controllerprocesses an image signal on the selected control data.
 2. An imagedisplay control apparatus according to claim 1, further comprising saidplurality of display devices having different optical characteristics.3. An image display control apparatus as claimed in claim 2, wherein:said detecting unit comprises an open-close detecting unit that detectsan open-close state of said display device as the operative state ofsaid display device.
 4. An image display apparatus as claimed in claim2, wherein: said detecting unit comprises a rotation detecting unit thatdetects an rotational state of said display device as the operativestate of said display device.
 5. An image display apparatus as claimedin claim 1, further comprising: a switching unit that switches an imagequality-prioritizing in which priority is given to an image quality ofan image to be displayed on one of said plurality of display devices,wherein said selecting unit selects a control data from the heldplurality of control data, according to the switching of said switchingunit.
 6. An image display apparatus as claimed in claim 1, wherein: thecontrol data comprises at least one characteristic selected from thegroup consisting of brightness, contrast, gamma, and white balance ofthe image signal.
 7. An image display apparatus as claimed in claim 1,wherein: said plurality of display devices comprise a first displaydevice and a second device, and the plurality of control data compriseat least two control data selected from the group consisting of a firstcontrol data that is most suitable for optical characteristics of thefirst display device, a second control data that is most suitable foroptical characteristics of the second display device, and a thirdcontrol data that is an approximately middle value of the first andsecond control data.
 8. An image display apparatus as claimed in claim7, wherein: the plurality of control data further comprise at least onecontrol data selected from the group consisting of a fourth control datathat is closer to the first control data with respect to theapproximately middle value, and a fifth control data that is closer tothe second control data with respect to the approximately middle value.9. An image display control apparatus as claimed in claim 7, wherein:the first display device is provided on the image display apparatus thatenables the first display device to be freely opened and closed andfreely rotated relative to the image display apparatus, and the seconddisplay device is fixed to the image display apparatus, and the imagedisplay control apparatus further comprises a control unit that controlsdisplay operations of the first display device and the second displaydevice, based on an open-close state and a rotational state of the firstdisplay device.
 10. An image display control apparatus as claimed inclaim 7, wherein: said plurality of display devices comprise liquidcrystal display panels.
 11. An image display control apparatus asclaimed in claim 2, further comprising: image capturing unit thatcaptures the image signal, wherein the image display control apparatusis handheld.
 12. An image display control method comprising the stepsof: holding a plurality of control data; processing an image signalbased on a control data, which determine a processing characteristic ofa common display controller, and outputting the processed image signalto a plurality of display devices; detecting operative states of saidplurality of display devices; and selecting one control data of the heldplurality of control data according to the detected operative states,wherein an image signal is processed on the selected control data.
 13. Anon-transitory computer-readable storage medium storing a programexecutable by a computer to execute an image signal processing method ofprocessing an image signal supplied to a plurality of display deviceshaving different optical characteristics, using a common displaycontroller that processes an image signal based on a plurality of datathat determine a processing characteristic of the common displaycontroller, and outputs the processed image signal to the plurality ofdisplay devices, the program comprising: a holding module for holdingthe plurality of the held data; a detecting module for detectingoperative states of the plurality of display devices; and a selectingmodule for selecting one of the held plurality of control data accordingto the detected operative states, wherein an image signal is processedon the selected control data.